Impact of residual spraying of bendiocarb against the malaria vector Anopheles culicifacies in selected villages of the Ghaziabad District, Uttar Pradesh, India.

A longitudinal study was carried out to evaluate the bioefficacy of indoor residual spraying of bendiocarb 80% wettable powder (WP) at 0.2 and 0.4 g/m2 against Anopheles culicifacies, a principle malaria vector, and the impact of bendiocarb use on malaria incidence in selected villages of the Ghaziabad District, Uttar Pradesh, India. The control village was sprayed with malathion at 1 g/m2 in 2001. Two rounds of bendiocarb spraying were carried out in each year from 1999 to 2001. Bendiocarb applications resulted in significant reduction in densities of adult An. culicifacies and other mosquito species in villages when compared to that of the control village (P < 0.05). Bioassay tests revealed that persistence of insecticide against An. culicifacies at 100% mortality was observed for about 10, 8, and 10 wk on mud, cement, and brick wall surfaces, respectively. Epidemiological evaluation revealed that malaria cases were significantly reduced after 1 year of spraying (P < 0.05) and by 2001, no Plasmodium falciparum was recorded in either of the bendiocarb-sprayed villages. The study revealed that indoor residual spraying of bendiocarb 80% WP at 0.2 g/m2 produced effective control of resistant An. culicifacies, provided that >95% human-dwelling room coverage is achieved in both 1st and 2nd rounds of spraying at an interval of 10 wk in areas where malaria is a seasonal problem.